Biology 1.2 - Ultrastructure of Cells

Question 1

What are the 2 different cell architectures? (U1)

Answer 1

Prokaryotic and eukaryotic cells.

Question 2

Which is the simpler cell type? (U1)

Answer 2

Prokaryotes have a simple cell structure without compartmentalization.

Question 3

Cell wall (prokaryote) (U1)

Answer 3

Protects and maintains shape.
Composed of carbs and proteins.
Some have additional layer to adhere structures (e.g. teeth, skin).

Question 4

Cell membrane (prokaryote) (U1)

Answer 4

Controls what goes in and out.
Big role in binary fission.
Cytoplasm is on the interior.
No compartments.
DNA is the most visible structure after passing the cell membrane.

Question 5

Pili (prokaryote) (U1)

Answer 5

Hollow hairlike structures.
Allow bacteria to attach to other cells.
Also allow for genetic information to be exchanged (conjugation).

Question 6

Flagella (prokaryote) (U1)

Answer 6

Used for motility.
Rotate like a motor.
Can be multiple.

Question 7

Ribosomes (prokaryote) (U1)

Answer 7

Site of protein synthesis.
Small, made up of two parts that come together, can be in large numbers.
Size: 70S.

Question 8

Nucleoid region (prokaryote) (U1)

Answer 8

DNA in the bacterial cell is genetically confined to this central region.
Not bounded by a membrane, but still visibly distinct from the rest of the cell interior.

Question 9

Plasmid (prokaryote) (U1)

Answer 9

DNA molecule that is seperate from the chromosomal DNA (can replicate on its own).
Double stranded and circular in shape.
Usually occur naturally in bacteria.

Question 10

How do prokaryotes divide? (A2)

Answer 10

Through binary fission.
Form of asexual reproduction.
2 DNA loops attach to membrane.
Membrane elongates and pinches off, forming 2 cells.
Daughter cells are clones (genetically identical).

Question 11

What do eukaryotes and prokaryotes have in common?

Answer 11

1. DNA
2. Cell membrane
3. Cytoplasm
4. Ribosomes

Question 12

What are the differences between eukaryotes and prokaryotes?

Answer 12

Prokaryote
1. DNA ring (no protein).
2. No nucleus (DNA is free).
3. No mitochondria.
4. 70S ribosomes.
5. No compartmentalization.
6. Less than 10 micrometers.
Eukaryotes
1. Chromosomes (linear, has protein holding it together).
2. Has nucleus.
3. Has mitochondria.
4. 80S organelles.
5. Greater than 10 micrometers.

Question 13

What is the advantage of eukaryotes having compartments? (U2)

Answer 13

Makes them more efficient as you can have different compartments performing different tasks at the same time.

Question 14

What are some eukaryotic cells? (U2)

Answer 14

Animals.
Algae.
Protozoa.
Fungi.
Plant.